So, I posted this problem on the Ubuntu forms and never got a real response, so I've decided to try posting this here, hoping someone could be of assistance.

I'm running Ubuntu Dapper Drake (6.06 LTS) and I'm attempting to run dual monitors through dual video cards. The main video card works fine, but from the second monitor I get nothing (just a black screen). The system recognizes both cards, because they're both showing up in the Device Manager, and I've installed Xinerama, so I'm not sure where the weak link is. Here are my basic system specs:

2.8GHz Pentium 4 Processor
2 GB RAM
nVidia GeForce 6200 AGP card
nVidia GeForce4 MX 4000 PCI card

Below you'll see the contents of my xorg.conf file. I followed the instructions on the Ubuntu forums for installing Xinerama to the letter, but something obviously didn't work because I still get nothing on the second monitor. (It's receiving power, it's plugged in, the card is recognized by the system. Not sure what I might've missed.) Any assistance folks could provide would be greatly appreciated. I've spent a couple weeks now trying to figure out what's wrong with no luck. Hopefully someone here can illuminate what I could've missed. Thanks again!

Code:
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder3) Mon Feb 26 23:38:46 PST 2007

# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the /etc/X11/xorg.conf manual page.
# (Type "man /etc/X11/xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Main Screen"
Screen 1 "Second Screen" LeftOf "Main Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
InputDevice "stylus" "SendCoreEvents"
InputDevice "cursor" "SendCoreEvents"
InputDevice "eraser" "SendCoreEvents"
Option "Xinerama" "true"
EndSection

Section "Files"

# path to defoma fonts
FontPath "/usr/share/X11/fonts/misc"
FontPath "/usr/share/X11/fonts/cyrillic"
FontPath "/usr/share/X11/fonts/100dpi/:unscaled"
FontPath "/usr/share/X11/fonts/75dpi/:unscaled"
FontPath "/usr/share/X11/fonts/Type1"
FontPath "/usr/share/X11/fonts/100dpi"
FontPath "/usr/share/X11/fonts/75dpi"
FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
Load "i2c"
Load "bitmap"
Load "ddc"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "type1"
Load "vbe"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc104"
Option "XkbLayout" "us"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ExplorerPS/2"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "true"
EndSection

Section "InputDevice"

# /dev/input/event
# for USB
Identifier "stylus"
Driver "wacom"
Option "Device" "/dev/wacom" # Change to
Option "Type" "stylus"
Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "InputDevice"

# /dev/input/event
# for USB
Identifier "eraser"
Driver "wacom"
Option "Device" "/dev/wacom" # Change to
Option "Type" "eraser"
Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "InputDevice"

# /dev/input/event
# for USB
Identifier "cursor"
Driver "wacom"
Option "Device" "/dev/wacom" # Change to
Option "Type" "cursor"
Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "Monitor"
Identifier "eView 15L"
Option "DPMS"
EndSection

Section "Monitor"
Identifier "Second Monitor"
Option "DPMS"
EndSection

Section "Device"
Identifier "0 NVIDIA Corporation 6200"
Driver "nvidia"
BusID "PCI:1:0:0"
Screen 0
Option "DDCMode" "True"
Option "MonitorLayout" "LFP,LFP"
EndSection

Section "Device"
Identifier "1 NVIDIA Corporation 4400"
Driver "nvidia"
BusID "PCI:0:7:0"
Screen 1
Option "DDCMode" "True"
Option "MonitorLayout" "LFP,LFP"
EndSection

Section "Screen"
Identifier "Main Screen"
Device "0 NVIDIA Corporation 6200"
Monitor "eView 15L"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
EndSection

Section "Screen"
Identifier "Second Screen"
Device "1 NVIDIA Corporation 4400"
Monitor "Second Monitor"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
EndSection